High-Pressure States of the Au₂₅ Cluster

In the present work, the effects of pressure on the electronic, vibrational, and structural properties of neutral and negatively charged Au 25 (SR) 18 clusters are investigated up to 15 GPa combining UV–vis absorption and Raman spectroscopy. We show that Au 25 (SR) 18 clusters undergo three structural transitions in the 0–15 GPa range located at around 0.8, 6, and 11 GPa. Results indicate that these phase transitions are intrinsic to the M 25 (SR) 18 structure and independent of the pressurization conditions, type of ligand, and charge state. The reported Raman measurements show that vibrational spectroscopy is a powerful tool for structural tracking of atomically precise metal nanoclusters under the application of pressure.